Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Mike
 
Posts: n/a
Default Convergence on PTV-375

I have a sylvania PTV-375 made by magnovox.

I made a costly costly mistake, i outta kick myself in the head for.

I changed the glycol, and the convergence was out. so, i didnt think that it
had a customer convergence menu, and i started out on the wave form board,
and tried to get it in, and never did.

I found the prints, that has the wiring diagram/convergence proceedure.

So, I attemped again. and followed the proceedure step by step, until i got
to the step and quote:

"3. to prevent customer controls from affecting adjustments, connect jumpers
between the following tie points (resistor junctions) and ground (pin8 of
IC17) on the convergence waveform panel: "1A"(R254/R252), "1B" (R260/R262),
"E" (R264/266), "F" (R256/R258),"

Well, i did this, and apparently they werent specific enough, because i
soldered the jumpers on the wrong side of teh resistors! so, i took out the
convergence board.

I'm pretty sure that IC17 is dead now, which takes care of the customer
convergence menu. and none of the knobs on the board function anymore.

the picture is smaller, and no longer centered. the supply rail resistors on
the convergence power board began to smoke, after i unsoldered. and opened.
it also opened 2 fuses on the power board also. i replaced all of that, and
tried again. with the jumpers off, and it opened the stuff again.

I disconnected the wave form board, and replaced the parts again. and this
time, the heatsinks are not too hot to touch as before, and the power board
is stable. but, there is no convergence obviously.

if i leave all the plugs in, the picture will shrink and start to smoke the
convergence power board again. I pulled the power connector to the wave form
board, and it stableized again. and of course, the customer convergence is
gone from the menu along with no response from board, because there is no
power.

I plugged the power connecter J607 back in, and unplugged J613 wich is the
convergence drive output, and the board was still stable, but no customer
convergence, and the board was getting power. So IC17, is fried becase there
is no menu for convergence anymore, and if i have both J607 and J613 plugged
in, it begins to smoke the convergence power board. im guessing the wave
form comming out of the wave form module, is so corrupted and noisy, its
overloading the power board and smoking the power resistors to the 20V
supply rail. The 12v supply rail is getting to the waveform board. if i pull
the power J607 the resistors dont smoke. if i plug it in, and unplug the
J613, it still dont smoke.

But, if both are plugged in like normal, it will smoke.

Any Ideas what IC on the wave form board seen its death besides IC17?

they need to be more specific where to jumper. because there is 2 sides to a
resistor. not one. the power board output transistors, and other various
components test fine. so the power board didnt go with it, its the signal
wave form board that is loading down, or overloading the power board with a
bad signal. of course, the convergence menu is gone now, and the board is
unresponsive.

help.


  #2   Report Post  
Mike
 
Posts: n/a
Default Convergence on PTV-375

anyone??



"Mike" wrote in message
...
I have a sylvania PTV-375 made by magnovox.

I made a costly costly mistake, i outta kick myself in the head for.

I changed the glycol, and the convergence was out. so, i didnt think that

it
had a customer convergence menu, and i started out on the wave form board,
and tried to get it in, and never did.

I found the prints, that has the wiring diagram/convergence proceedure.

So, I attemped again. and followed the proceedure step by step, until i

got
to the step and quote:

"3. to prevent customer controls from affecting adjustments, connect

jumpers
between the following tie points (resistor junctions) and ground (pin8 of
IC17) on the convergence waveform panel: "1A"(R254/R252), "1B"

(R260/R262),
"E" (R264/266), "F" (R256/R258),"

Well, i did this, and apparently they werent specific enough, because i
soldered the jumpers on the wrong side of teh resistors! so, i took out

the
convergence board.

I'm pretty sure that IC17 is dead now, which takes care of the customer
convergence menu. and none of the knobs on the board function anymore.

the picture is smaller, and no longer centered. the supply rail resistors

on
the convergence power board began to smoke, after i unsoldered. and

opened.
it also opened 2 fuses on the power board also. i replaced all of that,

and
tried again. with the jumpers off, and it opened the stuff again.

I disconnected the wave form board, and replaced the parts again. and this
time, the heatsinks are not too hot to touch as before, and the power

board
is stable. but, there is no convergence obviously.

if i leave all the plugs in, the picture will shrink and start to smoke

the
convergence power board again. I pulled the power connector to the wave

form
board, and it stableized again. and of course, the customer convergence is
gone from the menu along with no response from board, because there is no
power.

I plugged the power connecter J607 back in, and unplugged J613 wich is the
convergence drive output, and the board was still stable, but no customer
convergence, and the board was getting power. So IC17, is fried becase

there
is no menu for convergence anymore, and if i have both J607 and J613

plugged
in, it begins to smoke the convergence power board. im guessing the wave
form comming out of the wave form module, is so corrupted and noisy, its
overloading the power board and smoking the power resistors to the 20V
supply rail. The 12v supply rail is getting to the waveform board. if i

pull
the power J607 the resistors dont smoke. if i plug it in, and unplug the
J613, it still dont smoke.

But, if both are plugged in like normal, it will smoke.

Any Ideas what IC on the wave form board seen its death besides IC17?

they need to be more specific where to jumper. because there is 2 sides to

a
resistor. not one. the power board output transistors, and other various
components test fine. so the power board didnt go with it, its the signal
wave form board that is loading down, or overloading the power board with

a
bad signal. of course, the convergence menu is gone now, and the board is
unresponsive.

help.




  #3   Report Post  
BWL
 
Posts: n/a
Default Convergence on PTV-375

I might have an entire working convergence wave board; post the board number
and I'll check.
  #4   Report Post  
Mike
 
Posts: n/a
Default Convergence on PTV-375

00A10423-B002
CONV WAVE FORM BD
90351 M4T3 90



"BWL" wrote in message
...
I might have an entire working convergence wave board; post the board

number
and I'll check.



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mits VS60601 convergence JURB6006 Electronics Repair 4 October 13th 03 06:22 PM
Sony KP-61XBR200 convergence ideas? juice28 Electronics Repair 4 September 7th 03 11:19 PM
Toshiba TV Convergence Grid Pattern Not Showing. Barbizilla Electronics Repair 1 September 5th 03 12:29 PM
PTK195 convergence woes, intermittent of course JURB6006 Electronics Repair 0 July 25th 03 12:59 AM


All times are GMT +1. The time now is 12:54 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"